446 CBEMISTBY OF THE LEUCOMAINS. 



tion of polarized light is increased by acids (Lawrow). On heating 

 with baryta it becomes inactive (Siegfrid, Lawrow). For its be- 

 havior to phenyl isocyanate see ornithin. Henderson' examined 

 lysin from six different sources without finding any difference. 



The picrate," C,Ta.,,Nfi,.C,ll^l^flj, is difficultly soluble and is 

 therefore especially useful for the isolation of the base (p. 428). It 

 separates in large crystals, from solutions of the base in alcohol, on 

 the addition of sodium picrate. It is soluble in 185 parts of water 

 (Lawrow). 



The carbonate, 2C5Hi^NjOj + COj , was obtained in crystalline form 

 by Drechsel' and was regarded as analogous to ammonium car- 

 bamate. 



Phosphotungstic acid gives a precipitate which, when recrystallized 

 from much boiling water, forms needles (Kutscher^). 



Platinum chlorid precipitates lysin from alcoholic solution as 

 CgH„NjO,.2HCl.PtCl, + CjjHjO (Drechsel). It forms fine yel- 

 lowish red prisms from which the alcohol of crystallization can be 

 expelled by drying at 130°. It melts at 219°-220° (Schulze"). 



Lysin like arginin, forms two silver salts. The compound 

 CjHj^NjOj.AgNO, is more soluble than the corresponding one of 

 arginin and has been used as a means of separation (Hedin °). The 

 acid compound, CsHj^NjOj.HNOj'H- AgNOj, is easily soluble and 

 crystallizes from water by addition of alcohol and ether in beautiful 

 needles. 



Mercuric chlorid' does not precipitate dilute solutions of lysin 

 and arginin. The nitrate by itself does not precipitate lysin or 

 arginin but upon the addition of sodium hydrate these bases are 

 thrown down. 



With benzoyl chlorid* lysin forms a di-benzoyl derivative — 

 lysurio add — which corresponds to ornithuric and hippuric acids. 

 This compound forms acid as well as neutral salts which have been 

 studied by Drechsel and by Willdenow. The acid barium salt crys- 

 tallizes easily and is useful for the separation and purification of 

 lysin. In the presence of acids, lysurio acid is soluble in ether but 

 not in petroleum ether which therefore can be used for its separation 

 (Lawrow '). A mono-benzoyl derivative has also been prepared. 



Ornithin, Q^^^f>^, was discovered in 1877 by Jaff6 who ob- 

 tained it in the form of ornithuric acid from the urine of chicken 



^Zeils. phyM. Cheni., 29, 323. 



'Zeits-phyaiol. Chem., 25, 180 ; 26, 586 ; 28, 398 ; 33, 553. 



"Berichte, 25, 2455. 



*Zeits. physiol. Chem., 28, 89. 



^ZeifB. phyml. Chem., 28, 469 | 33, 661. 



' Zeits. physiol. Chem., 21, 300, 303. 



''Zeits. phyml. Chem., 21, 303 ; 25, 176. 



'SerieMe, 28, 3189 ; Zeits. physiol. Chem., 25, 622 ; 26, 398 ; 33, 562. 



^ Zeits. physiol. Chem., 28, 585. 



